The Vatican says Germany's Mercedes-Benz auto company is making a study of a hybrid, energy-saving popemobile that would replace the current Mercedes vehicle used when the pope travels abroad.

"It won't be ready for the September trip to Germany, but maybe at the end of the year or early next year," said Vatican spokesman the Rev. Federico Lombardi. Pope Benedict XVI is scheduled to make his first official visit to Germany Sept. 22-25.

Christian Anosowitsch, a spokesman for Mercedes in Stuttgart, Germany, said he could not confirm that the company was developing such a car, saying it is not policy to comment on possible future plans. "There is at the moment no order to build such a vehicle," he said.

Benedict has made conserving resources an important concern of his papacy. Solar panels have been installed on the roof of the papal audience hall at the Vatican.

Earlier this year there was talk of a solar-powered electric car as the next popemobile, but apparently this idea was discarded.

Officials said Benedict would gladly use such an electric vehicle as another sign of his efforts to promote sustainable energy and take care of the planet.

The Germany-based firm SolarWorld, which provided the photovoltaic cells on the auditorium, said it had discussed the idea. But its marketing chief said the main hurdle was to get Vatican security to agree since some still have concerns — unfounded, he said — that electric cars don't accelerate as quickly as traditional ones.

When he's outside the Vatican, Benedict usually rides in a modified white Mercedes-Benz outfitted with bulletproof windows. It has room for two passengers in addition to the pope, who sits on an elevated chair to wave to crowds.

Through the years, a number of different models have been donated to the Vatican, including a luxury Lancia limousine provided to Pope John Paul II in 1999 by Fiat that caused embarrassment over the cost.

An Italian auto magazine estimated the Lancia prototype cost nearly $1.5 million to develop, although Fiat issued a statement saying the figure was "far from reality." The Vatican, however, said at the time that had it known about the reported costs "the gift would not have been accepted."